feat(callgrind): add CALLGRIND_ADD_OBJ_SKIP client request

Add a trapdoor that lets the client register obj-skip paths at
runtime, alongside the existing cmdline --obj-skip. Useful when the
skip target isn't known statically (e.g. discovering the libpython
path at Python startup).

Extract CLG_(add_obj_to_skip) so the cmdline parser and the new
client request share the same append-to-realloc'd-array logic.

Author: not-matthias

callgrind/callgrind.h

@@ -78,7 +78,8 @@ typedef
       VG_USERREQ__TOGGLE_COLLECT,
       VG_USERREQ__DUMP_STATS_AT,
       VG_USERREQ__START_INSTRUMENTATION,
-      VG_USERREQ__STOP_INSTRUMENTATION
+      VG_USERREQ__STOP_INSTRUMENTATION,
+      VG_USERREQ__ADD_OBJ_SKIP
    } Vg_CallgrindClientRequest;
 
 /* Dump current state of cost centers, and zero them afterwards */
@@ -126,4 +127,10 @@ typedef
   VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__STOP_INSTRUMENTATION,  \
                                   0, 0, 0, 0, 0)
 
+/* Add an object file path to the obj-skip list at runtime. Path matching
+   is exact (same as --obj-skip=<path> on the command line). */
+#define CALLGRIND_ADD_OBJ_SKIP(path)                                 \
+  VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__ADD_OBJ_SKIP,          \
+                                  path, 0, 0, 0, 0)
+
 #endif /* __CALLGRIND_H */

callgrind/clo.c

@@ -400,6 +400,17 @@ void CLG_(update_fn_config)(fn_node* fn)
 }
 
 
+void CLG_(add_obj_to_skip)(const HChar* obj_name)
+{
+   HChar* dup = VG_(strdup)("cl.clo.aots.1", obj_name);
+   CLG_(clo).objs_to_skip_count++;
+   CLG_(clo).objs_to_skip = VG_(realloc)("cl.clo.aots.2",
+                                         CLG_(clo).objs_to_skip,
+                                         CLG_(clo).objs_to_skip_count * sizeof(HChar*));
+   CLG_(clo).objs_to_skip[CLG_(clo).objs_to_skip_count - 1] = dup;
+}
+
+
 /*--------------------------------------------------------------------*/
 /*--- Command line processing                                      ---*/
 /*--------------------------------------------------------------------*/
@@ -431,12 +442,7 @@ Bool CLG_(process_cmd_line_option)(const HChar* arg)
        fnc->skip = CONFIG_TRUE;
    }
    else if VG_STR_CLO(arg, "--obj-skip", tmp_str) {
-       HChar *obj_name = VG_(strdup)("cl.clo.pclo.1", tmp_str);
-       CLG_(clo).objs_to_skip_count++;
-       CLG_(clo).objs_to_skip = VG_(realloc)("cl.clo.pclo.2",
-                                             CLG_(clo).objs_to_skip,
-                                             CLG_(clo).objs_to_skip_count*sizeof(HChar*));
-       CLG_(clo).objs_to_skip[CLG_(clo).objs_to_skip_count-1] = obj_name;
+       CLG_(add_obj_to_skip)(tmp_str);
    }
 
    else if VG_STR_CLO(arg, "--dump-before", tmp_str) {

callgrind/global.h

@@ -685,6 +685,7 @@ struct event_sets {
 void CLG_(set_clo_defaults)(void);
 void CLG_(update_fn_config)(fn_node*);
 Bool CLG_(process_cmd_line_option)(const HChar*);
+void CLG_(add_obj_to_skip)(const HChar* obj_name);
 void CLG_(print_usage)(void);
 void CLG_(print_debug_usage)(void);
 

callgrind/main.c

@@ -1680,6 +1680,13 @@ Bool CLG_(handle_client_request)(ThreadId tid, UWord *args, UWord *ret)
      *ret = 0;                 /* meaningless */
      break;
 
+   case VG_USERREQ__ADD_OBJ_SKIP: {
+     const HChar* path = (const HChar*)args[1];
+     CLG_(add_obj_to_skip)(path);
+     *ret = 0;
+     break;
+   }
+
    case VG_USERREQ__GDB_MONITOR_COMMAND: {
       Bool handled = handle_gdb_monitor_command (tid, (HChar*)args[1]);
       if (handled)